3 files changed, 34 insertions, 8 deletions
diff --git a/src/widgets/widgets/qscrollbar.cpp b/src/widgets/widgets/qscrollbar.cpp
index efb17afedb..9ef56b7f95 100644
--- a/src/widgets/widgets/qscrollbar.cpp
+++ b/src/widgets/widgets/qscrollbar.cpp
@@ -476,8 +476,18 @@ bool QScrollBar::event(QEvent *event)
     if (const QHoverEvent *he = static_cast<const QHoverEvent *>(event))
         d_func()->updateHoverControl(he->pos());
         break;
+    default:
+        break;
+    }
+    return QAbstractSlider::event(event);
+}
+
+/*!
+    \reimp
+*/
 #ifndef QT_NO_WHEELEVENT
-    case QEvent::Wheel: {
+void QScrollBar::wheelEvent(QWheelEvent *event)
+{
         event->ignore();
         // override wheel event without adding virtual function override
         QWheelEvent *ev = static_cast<QWheelEvent *>(event);
@@ -492,14 +502,8 @@ bool QScrollBar::event(QEvent *event)
         Q_D(QScrollBar);
         if (d->scrollByDelta(ev->orientation(), ev->modifiers(), delta))
             event->accept();
-        return true;
-    }
-#endif
-    default:
-        break;
-    }
-    return QAbstractSlider::event(event);
 }
+#endif
 
 /*!
     \reimp
diff --git a/src/widgets/widgets/qscrollbar.h b/src/widgets/widgets/qscrollbar.h
index 95943f2676..48863616ff 100644
--- a/src/widgets/widgets/qscrollbar.h
+++ b/src/widgets/widgets/qscrollbar.h
@@ -67,6 +67,9 @@ public:
     bool event(QEvent *event);
 
 protected:
+#ifndef QT_NO_WHEELEVENT
+    void wheelEvent(QWheelEvent *);
+#endif
     void paintEvent(QPaintEvent *);
     void mousePressEvent(QMouseEvent *);
     void mouseReleaseEvent(QMouseEvent *);
diff --git a/tests/auto/widgets/widgets/qscrollbar/tst_qscrollbar.cpp b/tests/auto/widgets/widgets/qscrollbar/tst_qscrollbar.cpp
index 88c498cf07..4940372db9 100644
--- a/tests/auto/widgets/widgets/qscrollbar/tst_qscrollbar.cpp
+++ b/tests/auto/widgets/widgets/qscrollbar/tst_qscrollbar.cpp
@@ -56,6 +56,9 @@ public slots:
 private slots:
     void scrollSingleStep();
     void task_209492();
+#ifndef QT_NO_WHEELEVENT
+    void QTBUG_27308();
+#endif
 
 private:
     QScrollBar *testWidget;
@@ -143,5 +146,21 @@ void tst_QScrollBar::task_209492()
     QCOMPARE(spy.count(), 1);
 }
 
+#ifndef QT_NO_WHEELEVENT
+#define WHEEL_DELTA 120 // copied from tst_QAbstractSlider / tst_QComboBox
+void tst_QScrollBar::QTBUG_27308()
+{
+    // https://bugreports.qt-project.org/browse/QTBUG-27308
+    // Check that a disabled scrollbar doesn't react on wheel events anymore
+
+    testWidget->setValue(testWidget->minimum());
+    testWidget->setEnabled(false);
+    QWheelEvent event(testWidget->rect().center(),
+                      -WHEEL_DELTA, Qt::NoButton, Qt::NoModifier, testWidget->orientation());
+    qApp->sendEvent(testWidget, &event);
+    QCOMPARE(testWidget->value(), testWidget->minimum());
+}
+#endif
+
 QTEST_MAIN(tst_QScrollBar)
 #include "tst_qscrollbar.moc"